Date: Tue, 6 Jul 2021 16:01:25 -0700 From: Pete Wright via freebsd-stable <freebsd-stable@freebsd.org> To: Alan Somers <asomers@freebsd.org>, Pete French <petefrench@ingresso.co.uk> Cc: Stefan Esser <se@freebsd.org>, FreeBSD Stable Mailing List <freebsd-stable@freebsd.org> Subject: Re: ZFS + mysql appears to be killing my SSD's Message-ID: <2e6dbe13-e08f-1dab-1f5b-76a90c3a2ea7@nomadlogic.org> In-Reply-To: <CAOtMX2gWnEEKHHaDf0GmfC1wKAUqHK3ptNUxm23UFBsD_KHwKg@mail.gmail.com> References: <89c37c3e-22e8-006e-5826-33bd7db7739e@ingresso.co.uk> <2fd9b7e4-dc75-fedc-28d7-b98191167e6b@freebsd.org> <9c71d627-55b8-2464-6cc9-489e4ce98049@ingresso.co.uk> <CAOtMX2gWnEEKHHaDf0GmfC1wKAUqHK3ptNUxm23UFBsD_KHwKg@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On 7/5/21 7:51 AM, Alan Somers wrote: > > If you're using 4K sectors anyway, then GELI does not create any extra > write amplification. But if you're extra paranoid and you use the "-T" > option to "geli attach", then GELI will block TRIM commands. That could > hurt SSD lifetime. But I don't think "-T" is the default. You are using > 4K sectors, right? ZFS's ashift is set to 12? > -Alan > i also wonder if this could be a TRIM related issue. according to zpoolprops(8) TRIM is not enabled by default on pools - but it also has this note (see autotrim): "Be aware that automatic trimming of recently freed data blocks can put significant stress on the underlying storage devices. This will vary depending of how well the specific device handles these commands. For lower end devices it is often possible to achieve most of the benefits of automatic trimming by running an on-demand (manual) TRIM periodically using the zpool trim command." I wonder if adjusting the autotrim feature will address these issues - i manually enable autotrim for my pools and have seen no bad effects under quite of bit of bursty i/o. if it is enabled i wonder if the ssd you are using doesn't play nice with autotrim and should stay disabled? -p -- Pete Wright pete@nomadlogic.org @nomadlogicLA
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?2e6dbe13-e08f-1dab-1f5b-76a90c3a2ea7>